The patch titled Subject: mm/ksm: use folio in write_protect_page has been added to the -mm mm-unstable branch. Its filename is mm-ksm-use-folio-in-write_protect_page.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-ksm-use-folio-in-write_protect_page.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Alex Shi (tencent)" <alexs@xxxxxxxxxx> Subject: mm/ksm: use folio in write_protect_page Date: Thu, 11 Apr 2024 14:17:08 +0800 Compound page is checked and skipped before write_protect_page() called, use folio to save a few compound_head checking. Link: https://lkml.kernel.org/r/20240411061713.1847574-8-alexs@xxxxxxxxxx Signed-off-by: Alex Shi (tencent) <alexs@xxxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Izik Eidus <izik.eidus@xxxxxxxxxxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Chris Wright <chrisw@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/ksm.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) --- a/mm/ksm.c~mm-ksm-use-folio-in-write_protect_page +++ a/mm/ksm.c @@ -1289,23 +1289,24 @@ static u32 calc_checksum(struct page *pa return checksum; } -static int write_protect_page(struct vm_area_struct *vma, struct page *page, +static int write_protect_page(struct vm_area_struct *vma, struct folio *folio, pte_t *orig_pte) { struct mm_struct *mm = vma->vm_mm; - DEFINE_PAGE_VMA_WALK(pvmw, page, vma, 0, 0); + DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, 0, 0); int swapped; int err = -EFAULT; struct mmu_notifier_range range; bool anon_exclusive; pte_t entry; - pvmw.address = page_address_in_vma(page, vma); + if (WARN_ON_ONCE(folio_test_large(folio))) + return err; + + pvmw.address = page_address_in_vma(&folio->page, vma); if (pvmw.address == -EFAULT) goto out; - BUG_ON(PageTransCompound(page)); - mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, pvmw.address, pvmw.address + PAGE_SIZE); mmu_notifier_invalidate_range_start(&range); @@ -1315,12 +1316,12 @@ static int write_protect_page(struct vm_ if (WARN_ONCE(!pvmw.pte, "Unexpected PMD mapping?")) goto out_unlock; - anon_exclusive = PageAnonExclusive(page); + anon_exclusive = PageAnonExclusive(&folio->page); entry = ptep_get(pvmw.pte); if (pte_write(entry) || pte_dirty(entry) || anon_exclusive || mm_tlb_flush_pending(mm)) { - swapped = PageSwapCache(page); - flush_cache_page(vma, pvmw.address, page_to_pfn(page)); + swapped = folio_test_swapcache(folio); + flush_cache_page(vma, pvmw.address, folio_pfn(folio)); /* * Ok this is tricky, when get_user_pages_fast() run it doesn't * take any lock, therefore the check that we are going to make @@ -1340,20 +1341,20 @@ static int write_protect_page(struct vm_ * Check that no O_DIRECT or similar I/O is in progress on the * page */ - if (page_mapcount(page) + 1 + swapped != page_count(page)) { + if (folio_mapcount(folio) + 1 + swapped != folio_ref_count(folio)) { set_pte_at(mm, pvmw.address, pvmw.pte, entry); goto out_unlock; } /* See folio_try_share_anon_rmap_pte(): clear PTE first. */ if (anon_exclusive && - folio_try_share_anon_rmap_pte(page_folio(page), page)) { + folio_try_share_anon_rmap_pte(folio, &folio->page)) { set_pte_at(mm, pvmw.address, pvmw.pte, entry); goto out_unlock; } if (pte_dirty(entry)) - set_page_dirty(page); + folio_mark_dirty(folio); entry = pte_mkclean(entry); if (pte_write(entry)) @@ -1519,7 +1520,7 @@ static int try_to_merge_one_page(struct * ptes are necessarily already write-protected. But in either * case, we need to lock and check page_count is not raised. */ - if (write_protect_page(vma, page, &orig_pte) == 0) { + if (write_protect_page(vma, page_folio(page), &orig_pte) == 0) { if (!kpage) { /* * While we hold page lock, upgrade page from _ Patches currently in -mm which might be from alexs@xxxxxxxxxx are mm-ksm-add-ksm_get_folio.patch mm-ksm-use-folio-in-remove_rmap_item_from_tree.patch mm-ksm-add-folio_set_stable_node.patch mm-ksm-use-folio-in-remove_stable_node.patch mm-ksm-use-folio-in-stable_node_dup.patch mm-ksm-use-ksm_get_folio-in-scan_get_next_rmap_item.patch mm-ksm-use-folio-in-write_protect_page.patch mm-ksm-convert-chain-series-funcs-and-replace-get_ksm_page.patch mm-ksm-replace-set_page_stable_node-by-folio_set_stable_node.patch